alpha: move from strlcpy with unused retval to strscpy

[PATCH] alpha: move from strlcpy with unused retval to strscpy

Posted by Wolfram Sang 3 years, 7 months ago

Follow the advice of the below link and prefer 'strscpy' in this
subsystem. Conversion is 1:1 because the return value is not used.
Generated by a coccinelle script.

Link: https://lore.kernel.org/r/CAHk-=wgfRnXz0W3D37d01q3JFkr_i_uTL=V6A6G1oUZcprmknw@mail.gmail.com/
Signed-off-by: Wolfram Sang <wsa+renesas@sang-engineering.com>
---
 arch/alpha/kernel/setup.c | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/arch/alpha/kernel/setup.c b/arch/alpha/kernel/setup.c
index b4fbbba30aa2..33bf3a627002 100644
--- a/arch/alpha/kernel/setup.c
+++ b/arch/alpha/kernel/setup.c
@@ -491,9 +491,9 @@ setup_arch(char **cmdline_p)
 	   boot flags depending on the boot mode, we need some shorthand.
 	   This should do for installation.  */
 	if (strcmp(COMMAND_LINE, "INSTALL") == 0) {
-		strlcpy(command_line, "root=/dev/fd0 load_ramdisk=1", sizeof command_line);
+		strscpy(command_line, "root=/dev/fd0 load_ramdisk=1", sizeof(command_line));
 	} else {
-		strlcpy(command_line, COMMAND_LINE, sizeof command_line);
+		strscpy(command_line, COMMAND_LINE, sizeof(command_line));
 	}
 	strcpy(boot_command_line, command_line);
 	*cmdline_p = command_line;
-- 
2.35.1

Re: [PATCH] alpha: move from strlcpy with unused retval to strscpy

Posted by Joe Perches 3 years, 7 months ago

On Thu, 2022-08-18 at 22:59 +0200, Wolfram Sang wrote:
> Follow the advice of the below link and prefer 'strscpy' in this
> subsystem. Conversion is 1:1 because the return value is not used.
> Generated by a coccinelle script.

Nice.

Last time I posted a coccinelle script for strlcpy->strscpy conversions
with unused returns, there were several variants that were not converted.

https://lore.kernel.org/cocci/a3279a5772b2e49b57890cd75e97360b82890798.camel@perches.com/T/#m502108bfe0cc6a41d499a4c1b55d5f5db1423465

Did you post the script you used?

Re: [PATCH] alpha: move from strlcpy with unused retval to strscpy

Posted by Wolfram Sang 3 years, 7 months ago

Hi Joe,

Glad you like this series.

> Last time I posted a coccinelle script for strlcpy->strscpy conversions
> with unused returns, there were several variants that were not converted.
> 
> https://lore.kernel.org/cocci/a3279a5772b2e49b57890cd75e97360b82890798.camel@perches.com/T/#m502108bfe0cc6a41d499a4c1b55d5f5db1423465
> 
> Did you post the script you used?

First version here, very similar to yours:

https://lore.kernel.org/all/YvhXzarjOLEJ8nsW@shikoro/

The final version has another rule to add missing parens to the argument
of a sizeof operator:

@ main @
@@
- strlcpy
+ strscpy
  (...);

// make sure sizeof always has parens. Isomorphs will remove existing ones if present before.
@ add_parens depends on main @
expression dst, src, E;
@@
  strscpy(dst, src,
- sizeof(E)
+ sizeof(E)
  );

Like your try, some header files are missing. I guess Julia's remarks
about that from the thread above will fix this as well. However, since
there are the instances left where the return value of strlcpy is used
anyhow, I left those for manual fixing.

Thanks,

   Wolfram